Cactus must “sleep” in the winter and stay from September through March without water (in winter there is little sun and cactus suffers). Most of Cacti are blooming from spring until autumn. Schlumbergera is winter- blooming cactus and grows very well in the apartment. Gymnocalycium is a cactus of easy cultivation.

Thank you for your reply. It is very interesting. Do you know “Prickly Pears”? They are the fruit of some cacti. The fruit is sweet and full of little black seeds inside. For some pictures, you can look in Wikipedia under “Opuntia”.